From 87994979076e69e61a46b74b7541b72fd5473d7a Mon Sep 17 00:00:00 2001
From: yuzelin <zelin.yzl@alibaba-inc.com>
Date: Sat, 3 Aug 2024 17:05:10 +0800
Subject: [PATCH] refactor

---
 .../parquet/reader/NestedPositionUtil.java    | 41 +++++--------------
 1 file changed, 11 insertions(+), 30 deletions(-)

diff --git a/paimon-format/src/main/java/org/apache/paimon/format/parquet/reader/NestedPositionUtil.java b/paimon-format/src/main/java/org/apache/paimon/format/parquet/reader/NestedPositionUtil.java
index 62338278512a..9757b94c7583 100644
--- a/paimon-format/src/main/java/org/apache/paimon/format/parquet/reader/NestedPositionUtil.java
+++ b/paimon-format/src/main/java/org/apache/paimon/format/parquet/reader/NestedPositionUtil.java
@@ -24,8 +24,6 @@
 import org.apache.paimon.utils.BooleanArrayList;
 import org.apache.paimon.utils.LongArrayList;
 
-import java.util.Arrays;
-
 import static java.lang.String.format;
 
 /** Utils to calculate nested type position. */
@@ -108,42 +106,29 @@ public static CollectionPosition calculateCollectionOffsets(
                 i < definitionLevels.length;
                 i = getNextCollectionStartIndex(repetitionLevels, collectionRepetitionLevel, i)) {
             if (definitionLevels[i] >= collectionDefinitionLevel - 1) {
-                valueCount++;
-
-                boolean isNull =
-                        isOptionalFieldValueNull(definitionLevels[i], collectionDefinitionLevel);
-                if (isNull) {
-                    nullCollectionFlags.add(true);
-                    nullValuesCount++;
-                    // 1. don't increase offset for null values
-                    // 2. offsets and emptyCollectionFlags are meaningless for null values, but they
-                    // must be set at each index for calculating lengths later
-                    offsets.add(offset);
-                    emptyCollectionFlags.add(false);
-                    continue;
-                }
-
-                nullCollectionFlags.add(false);
                 // definitionLevels[i] > collectionDefinitionLevel  => Collection is defined and not
                 // empty
                 // definitionLevels[i] == collectionDefinitionLevel => Collection is defined but
                 // empty
+                // definitionLevels[i] == maxDefinitionLevel - 1 => Collection is defined but null
                 if (definitionLevels[i] > collectionDefinitionLevel) {
+                    nullCollectionFlags.add(false);
                     emptyCollectionFlags.add(false);
                     offset += getCollectionSize(repetitionLevels, collectionRepetitionLevel, i + 1);
                 } else if (definitionLevels[i] == collectionDefinitionLevel) {
-                    // don't increase offset for empty values
+                    nullCollectionFlags.add(false);
                     emptyCollectionFlags.add(true);
+                    // don't increase offset for empty values
                 } else {
-                    throw new IllegalStateException(
-                            String.format(
-                                    "This case should be handled as null value. "
-                                            + "index: %d, definitionLevels: %s, collectionDefinitionLevel: %s.",
-                                    i,
-                                    Arrays.toString(definitionLevels),
-                                    collectionDefinitionLevel));
+                    nullCollectionFlags.add(true);
+                    nullValuesCount++;
+                    // 1. don't increase offset for null values
+                    // 2. offsets and emptyCollectionFlags are meaningless for null values, but they
+                    // must be set at each index for calculating lengths later
+                    emptyCollectionFlags.add(false);
                 }
                 offsets.add(offset);
+                valueCount++;
             }
             // else when definitionLevels[i] < collectionDefinitionLevel - 1, it means the
             // collection is not defined, just ignore it
@@ -157,10 +142,6 @@ public static CollectionPosition calculateCollectionOffsets(
                 nullCollectionFlags.toArray(), offsetsArray, length, valueCount);
     }
 
-    public static boolean isOptionalFieldValueNull(int definitionLevel, int maxDefinitionLevel) {
-        return definitionLevel == maxDefinitionLevel - 1;
-    }
-
     public static long[] calculateLengthByOffsets(
             boolean[] collectionIsEmpty, long[] arrayOffsets) {
         LongArrayList lengthList = new LongArrayList(arrayOffsets.length);